Inner tube construction



19,1952 c. E. SNYDER. I *256Q7, 392 I INNER TUBE CONSTRUCTION Filed April 25, 1949 JET/5212272.

575551755 'E-SL QER Patented Aug. 19, 1952 INNE I t TUBE CONSTRUCTION Clarence E. Snyder, Akron, Ohio, assignor to The B. F. Goodrich Company, New York, N. Y., a-

corporation of New York Application April 23, 1949, Serial No. 89,263 W This invention relates to inner tubes and to the manufacture thereof, and especially to inner tubes such as are used on aircraft which are subject to high impact forces and have reinforcements disposed at the inner faces for protecting the inner tubes from chafing and other damage in use and installation.

Such reinforcements, usually of cord fabric, have been built into the rim-side faces of the inner tubes to protect the tubes from chafing damage caused by the rocking of the tire beads under excessive impact forces. However prior reinforcements have resulted in the difficulty of weakness in the inner tubes at the edges of the reinforcing fabric because of the, localized stresses concentrated in the tube wall at the termination of the fabric where the rubber is often abruptly and severely stretched. Also, difiiculty has been encountered because of the trapping of air in this region during the building.

Objects of the invention are to provide for overcoming and avoiding the foregoing and other difliculties, to provide an improved reinforced inner tube construction, to provide with a chafer reinforcement a reinforcing strip which will strengthen the inner tube at the edges of the reinforcing band without introducing the objectionable characteristics discussed hereinabove, to provide improved distribution of the stresses within the inner tube at the edges of the reinforcing band, and to facilitate manufacture of the inner tube.

These and other objects will be apparent from the following description, reference being had to the drawings in which:

Fig. 1 is an elevation of an inner tube constructed in accordance with' and embodying the invention.

Fig. 2 is a section in perspective taken along line 2-2 of Fig. 1.

Fig. 3 is a section of the tube shown in Fig. I mounted on a rim within a tire shown in broken lines.

Fig. 4 is a sectional view on an enlarged scale of the tube prior to vulcanization showing the construction of the base portion.

Fig. is a section in perspective of the rubber reinforcing strip shown in Fig. 4.

With reference to the drawing, an inner tube I0 constructed in accordance with and embodying the invention is shown in Fig. 1. The inner tube I0 of the invention has a hollow toroidal l I mounted thereon through which the tube may be inflated and deflated.

As shown in Fig. 2 a reinforcement I2 to resist chafing action is disposed at the rim side face of the inner tube Ill, secured to and partially sonims'. (01. 152 -350)? embedded in the rubber'.-and maybe of a'suitablereinforcing fabric such 1 as woven rayon, nylonor cotton. The 'fabric f the reinforcement I2 is preferably cut and mounted on the bias and extends circumferentially of the inner tube at-the surface-which engages rim I3 of a supported wheel and engages bead portions I4, I4 of an enclosing tire I5 as shown in Fig. 3.

The reinforcement I2 has edges I6, I6 whichare embedded in thickened portions l1, ll of theinner tube I6 so that the edges are covered by substantially thick layers'of resilient rubber material of the tube to distribute stresses whichdevelop at the edges during operation, andavert objectionable localized stresses in this region. The thickened portions l1, ll of the inner tube I 0 are thickest at the sections closest to the edges I6, I6 of the reinforcement I2 and the sections of the portions I1; I! are reduced in thickness in small'increments as the sections become more remote from the edges of the reinforcement until the standard thickness of the inner tube wall is reached at the edges of the thickened portion. In this manner a tapered constructionis provided which effectively distributes the stresses developed at the edges I6, I6 of the reinforcement I2 and provides a smooth surface of the inner tube l6 without the introduction of weakening irregularities.

In construction of the inner tube III of the'iiivention a tubular body I8 of resilient-rubberf or other rubber-like material'may be formed in a suitable manner such as by extrusion. The reinforcement I2 is preferably prepared by fric-" tioning the resilient rubber on a bias cut band" I9 of suitable fabric such as nylon, rayon or: cotton after which the band may be adhesively applied to the face of the tubular body I8 and suitably adhered thereto as by cementing.

A reinforcing strip 20 which is constructed in accordance with and embodying the invention is shown in Fig. 5 in the form prior to vulcanizaface in which there is a flat portion 2I and an-' other flat portion 22 separated by a step. 23 of a depth corresponding with the thickness of the reinforcement I2. The step23 makes possible the reception of the fabric I2 upon the flat porf tion 2| of the strip 20 so that the reinforcement I2 will lie substantially flush with the other flat portion 22 of the strip 26. The reinforcing strip is thereby mounted over the edges I6, I6 of the fabric band I9 and may be rolled and pressed into place without leaving any air spaces between the tubular body I8 and strip 26. The strip 26 is thick in the section containing the step 23 lation with the edges l6, l6 of the reinforcing fabric IS, the two ends of the tubulanbodyare attached in abutting relation in a suitable m'anner as by butt splicing. 'Ihexass'embled tube l0.

tube and said reinforcing strip having a relatively thick stepped recessed portion for receiving an edge ofthe reinforcement inffiu's'h relation.

inner tube reinforcing strip for overlap- 5 ping disposition at the edges of a reinforcement Qdisposed at the rim-side of the inner tube, said -reinforcing strip comprising an elongated strip of rubbermaterial not fully vulcanized having a -.relatively' thickcentral portion and a face therethen may be cured and vulcanized invany-suitablejq'ohavingata said central portion a stepped pormanner, preferably in a mold under fluid pressure within the tube.

As a result of the close fit of the strip'20 over the edge of the fabric as provided by the-SstepEtZS in the face of the strip and the graduated thickness of the strip from. the. central region to- 'its margin, :the, possibility .-.of air being trapped-at thisijointflsminimized and the dispositionzof {the rubbenin the regionatrthe 'edgeiof. the fabric l9 isrefiectivezin distributing stresses in the molded tube and avoiding obj ectionableloca'lized concentrationstthereof for-obtaining maximum life oftthe tube even though:itbe:subjected to zhigh impact stressesrin 'use with the raccompanyingv chafing action from. rocking--actioni-of*the :beads .under extreme contraction of the tire.

Variations may be made without departing fromwthescope of "the :inventionas .it is defined inthe following claims.

,Iclaim: i

1. An inflatable tireinner..tubercomprisinga bodypf resilient rubber *material having. :a reinforcement. secured tto and forming; apartof said body-at therim side :f-aceZthereof and terminating in anedgeoisposed in .-.the :tire bead region of .the; tube and'aa-reinforcing strip. of. resilient rubber material having in its shap prior to-vulcanization" asteppe d face, said strip being.- disposed :with saidedge-of .the reinforcement .inthe step :of saidstrip and-being united with said body. byvulcani-.- zationfi-undermolding pressure.

An linfiatable: tiretinner tube comprisinga body. of resilient rubber -material rhavingr .fabric chafer reinforcement secured to andforming: a partof: said: body at the rim-sideface. thereof extending across and-along said face and terminating in an edge-disposed'in the tire bead region of the'tube and a reinforcing stripof resilient rubber material .havingin its shape prior-to vulcanization a stepped face-said strip beingsdisposed-with said edge of. the fabric in-the. .step of said: strip and "beingunited with said: -=body =by vulcanization undermolding pressure. v

3. An -.-infiatab1e tireinner tube comprisingaa body .of. resilient rubber material having-a=fabric chafer: reinforcement -secured to and forming a partrofn-said body at ..the rimeside .face...ther.eof extendingacross and-along said face and .terminating in an edge disposedin thetire head region. ofc-t-he. .tube,- and a reinforcing. strip .of resilient, rubbersmaterialhaving in'itszshape prior to vulcanization a .thick central portion and ata face thereoffhavinga stepped face, said strip being disposed with said edge of the fabric inthe step of said s't'ripand beingunited with said body .by vulcanization, andv said strip tapering from :said thick centralv portion to thin edges at the margins of the'str'ip.

4. Aniinner tubereinforcing strip for overlapping disposition at the edges of a reinforcement disposedat the rim-side face of the inner tionw-ithiithe: "step extending longitudinally of said strip andenadjacent recessed portion for receiving an edge of the reinforcement in flush :relation.

6. An inner tube reinforcing strip for overlapping..disposition= at theledges of a. reinforcement disposed-at. the rim-side facebfthe inner tube, said.v reinforcing -.strip comprising an elongated stripof rubber .materialnot fully vulcanized-having-.a relatively thick central portion and at azface thereof having at vsaid central-portion. a stepped portion with the step extending longitudinally of said strip and.an.adjacentrecessed portion for receiving-lanedge of the. reinforcement in flush relation, said elongated strip.taperingirom-said thick central portion to thin edges atthe. margins of'the strip. v

'7. Themethod of .making .an inflatable tire inner tube which. comprises .forming a .bodyof rubber material, incorporating therein attherimside. face thereof a reinforcement. withanedge thereof .disposed in the tire. bead region of the tube, forming, a reinforcing-'stripof rubber-like materialhaving a stepped fac e,.applying said strip to said body with said edge-of said reinforcement disposed 'in'the-step of said strip, and vulcanizing the assembly under moldingpressure thereby uniting said. strip with said body.

8. A'"m'et hod of making an inflatable .tire inner tube which comprises forming an open-ended tubular. body .of resilient rubbermaterial, incorporating therein at a facethereof a fabric. bahdwith edges disposed at the face in the tirebead'region of'the tube, forming areinforcing strip. of rubberlikematerial having a. face. with a stepped-portionthereon, applying said strip in adhered relation to said body with an edge of said fabric hand disposed in the step .of said strip in substantially fiushcondition with said step, splicingtheends of the'reinforced tubularbody and. vulcanizing the assembly under molding pressure thereby uniting said stripwithfsaid body.

CLARENCE E. SNYDER.

REFERENCES CITED .The' following references are of record in the file. of this" patent:

UNITED STATES. PATENTS Number I Name Date 467,502 Gray; Jan; 26, 1892 497,971 Ti1linghast. ,May 23, 1893 554,711 Moomy Feb. 18, 1896 1,162,745 Blodgett Dec. 7, 1915 5 1,252,107 Haigler "-1 Jan. 1, 1918 1,474,085 -Meredith Nov. 13, 1923 1,822,563 .Eger Sept. 8, 1931 FOREIGNv PATENTS Number Country Date France Oct. 16, 1917 

